Device for constructing a foundation in soft soil formations

Abstract

The present invention relates to a device for constructing a tubular pile foundation in soft soil formations. Where in use, the device is suspended into the soft soil from a crane or a derrick on the earth or a working barge off shore. The device for stabilizing a body of the soft soil comprises a machine box holding driving means, driving shaft means connected to said drive means, agitating barrel means for stirring the soft soil disposed at the lower end of said driving shaft means, said agitating barrel means having a plurality of agitating blades, and a chemical hardener feeder system for injecting the hardener into the soft soil to form solidified tubular piles, said chemical hardener feeder system including swivel joints, delivery pipes and injection nozzles. The device can be moved upward and downward in course of constructing tubular solid piles in situ by agitating and mixing the soil with the hardener to provide the high bearing capacity to the soil layers.

What is claimed is: 
     
       1. A device for constructing a tubular pile foundation in soft soil formations comprising: a machine box in which drive means is accepted;   said drive means including a motor and at least one gear reducer;   driving shaft means connected to said gear reducer;   barrel means disposed at the lower end of said driving shaft means;   a plurality of blades for agitating the soil in annular shape arranged on the inner and outer faces of said agitating barrel means;   swivel joint means disposed beneath said machine box;   pipe means adjacent to and parallel with said driving shaft means for delivering chemical hardener, said pipe means being connected to said swivel joint means and extending to the lower end of said barrel means; and   nozzle means formed at the tip end opening of said pipe means for injecting chemical hardener into the soil;   wherein the device is used to construct a tubular pile foundation in the soft soil formations with individual tubular piles or jointed tubular piles each having an annular cross section.   
     
     
       2. A device as claimed in claim 1, wherein said driving shaft means includes a plurality of tubular shafts, each of said tubular shafts having a diameter similar to the diameter of said barrel. 
     
     
       3. A device as claimed in claim 2, wherein said a plurality of tubular shafts consist of at least one pair of them and one of each paired shafts rotates in opposite direction to the other to eliminate reaction forces exerted by each driving shaft on the whole. 
     
     
       4. A device as claimed in claim 1, wherein said driving shaft means includes a plurality of rod-like shafts. 
     
     
       5. A device as claimed in claim 1, wherein said a plurality of rod-like shafts consist of at least one pair of them and one of each paired shafts rotates in opposite direction to the other to eliminate reaction forces exerted by each driving shaft on the whole. 
     
     
       6. A device as claimed in claim 1, further comprising second nozzle means communicating with said pipe means for delivering chemical hardener into the soil adjacent the upper end of said barrel means.